In 250 AD the Emperor Decius (249-251) ordered that all citizens of the Empire make a public sacrifice to the gods. It was a perfect way to trap Christians whose faith called them to reject any form of idolatry. Those Christians who publicly refused to worship the false gods were either sent into exile, thrown into prison or, as in many cases, executed. Unfortunately, some of the faithful chose to apostatize - to abandon the faith - and offered a sacrifice to the gods rather than undergo imprisonment and exile.
When the persecutions came to an end, the Church was faced with a difficult matter. It had to decide how it was going to handle those Catholics who offered a sacrifice to the pagan gods, but now wanted to be readmitted into the Church. This led to a heresy, started by a priest in Rome named Novatian, who insisted that those who were guilty of serious sin, such as apostasy, should be excommunicated and never allowed back into communion with the Church. Pope Cornelius in 251 AD condemned Novatian's theology insisting that even though one committed a serious sin they could still, through prayer and severe penance, be allowed back into the Church.
This century also witnessed the beginnings of monasticism in Egypt. A number of Christians through the inspiration of the Holy Spirit, left the world and all its comforts to literally follow Christ into the desert and lead austere and holy lives. Two men who contributed greatly to this way of life were St. Anthony of Egypt (251-356) and St. Pachomius (292-346).
St. Anthony, after hearing a passage from the Gospel where Jesus spoke about leaving everything behind to follow Him, abandoned his family farm and moved to the desert. While in the desert he lived as a hermit, embracing a life of severe penance, constant prayer and labor. His reputation as a holy man of God attracted others to follow his way of life and example. St. Pachomius on the other hand built and founded several monasteries in the Egyptian desert where men lived together in a communal environment.